Stages of Bodily Decomposition
I found this to be really intriguing. Hard to believe the human body is reduced to this process. Still trying to picture myself going through such a reversed metamorphosis. I grabbed and copied this delightful info from this link:
Once death occurs, human decomposition takes place in stages. The process of tissue breakdown may take from several days to years.
The fresh stage of decomposition occurs during the first few days following death. There are no physical signs of decomposition during this time. However, homeostasis of the body has ceased to function which allows cellular and soft tissue changes to occur because of the process of autolysis, the destruction of cells and organs due to an aseptic chemical process. At this point, the body enters algor mortis, the cooling of the body’s temperature to that of its surroundings. When the body’s cells reach the final stage of autolysis, an anaerobic environment is created. This allows the body’s normal bacteria to breakdown the remaining carbohydrates, proteins, and lipids. The products from the breakdown create acids, gases, and other products which cause volatile organic compounds (VOCs), and putrefactive effects. According to Science Direct, VOCs are produced during the early stage of human decomposition.
Odor, color changes, and bloating of the body during decomposition are the results of putrefaction. The lower part of the abdomen turns green due to bacteria activity in the cecum. Bacteria break down hemoglobin into sulfohemoglobin which causes the green color change. A formation of gases enters the abdomen which forces liquids and feces out of the body. The gases also enter the neck and face, causing swelling of the mouth, lips, and tongue. Due to this swelling and disconfiguration of the face, identification of the body can be difficult. Bacteria also enter the venous system causing blood to hemolyze. This leads to the formation of red streaks along the veins. This color soon changes to green, through a process known as marbelization. It can be seen on the shoulders, chest and shoulder area, and thighs. The skin can blister and have a serous fluid inside. The skin also becomes fragile, leading to skin slippage, making it difficult to move a body. Body hair comes off easily. The color change of the discoloration from green to brown marks the transition of the early stage of putrefaction to the advanced decompositional stages.
After the body goes through the bloating stage it begins the black putrefaction stage. At this point the body cavity ruptures, all of the abdominal gases begin to escape and the body darkens from its greenish color. These activities allow for a greater invasion of scavengers, and insect activity increases greatly. This stage ends as the bones become apparent, which can take anywhere from 10 to 20 days after death depending on region and temperature. This period is also dependent on the degree to which the body is exposed.
After the early putrefaction and black putrefaction phases have taken place, the body begins mummification, in which the body begins to dry out. The human carcass is first mummified, and then goes through adipocere formation. Adipocere (grave wax) formation refers to the loss of body odor and the formation of a cheesy appearance on the cadaver. Mummification is considered a post-active stage because there is less definite distention between changes and they are indicated by reduced skin, cartilage, and bone. Mummification is also indicated when all of the internal organs are lost due to insect activity.
When the last of the soft-tissue has been removed from the body, the final stage of decomposition, skeletonization, occurs. This stage encompasses the deterioration of skeletal remains, and is the longest of the decomposition processes. Skeletonization differs markedly from the previous stages, not only in length, but in the deterioration process itself.
Substances produced during the fresh stage attract a variety of insects. Many of the Diptera insects begin to lay their eggs on the body during this stage, especially the Calliphoridae. There is also considerable insect activity by the insects that live in the soil around the body.
Importance to forensics
Various sciences study the decomposition of bodies. These sciences fall under the general rubric of forensics, because the usual motive for study of the decomposition of human bodies is to determine the time and cause of death, for legal purposes:
- Forensic pathology studies the clues to the cause of death found in the corpse as a medical phenomenon
- Forensic entomology studies the insects and other vermin found in corpses; the sequence in which they appear, the kinds of insects, and where they are found in their life cycle are clues that can shed light on the time of death, the length of a corpse’s exposure, and whether the corpse was moved.
- Forensic anthropology is the branch of physical anthropology that studies skeletons and human remains, usually to seek clues as to the identity, race, and sex of their former owner.